Universal Mobile Telecommunication Service (UMTS) system is a 3rd Generation asynchronous mobile communication system based on Global System for Mobile Communication (GSM) and General Packet Radio Services (GPRS) and using Wideband Code division Multiple Access (WCDMA).
The 3rd Generation Partnership Project (3GPP), in charge of standardization of UMTS, is now working on Long Term Evolution (LTE) as the next generation mobile communication system. LTE is a technology for realizing 100 Mbps high-speed packet based-communication and is scheduled to be commercialized by 2010. In order to meet the requirement, various techniques discussed. Some of these techniques can be to reduce a number of nodes on the communication channel and to arrange wireless protocols close to wireless channels.
In case of LTE in which communication is performed with the resources allocated based on the per-packet scheduling, frequent transmission of control information such as scheduling request and resource allocation information causes traffic overload. In order to solve this problem, Semi-Persistent Scheduling (SPS) is adopted.
In the SPS, the base station notifies a user terminal of the allocated SPS resource and size of MAC PDU to be transmitted on the SPS resource. Upon receipt of the information on the SPS resource allocation, the user terminal can transmit MAC PDUs on the SPS resource without exchange of additional control signals. In order to check the SPS resource allocated itself, the user terminal performs Cyclic Redundancy Checking (CRC). If the CRC fails, the user terminal may misjudge the allocation of SPS resource even though no SPS resource has been allocated. In this case, the user terminal transmits the data continuously on the misjudged SPS resource, resulting in waste of transmission resource allocation. There is therefore a need to develop of an efficient resource allocation method that is capable of reducing the waste of transmission resource.